Sanding device



Jamx 7, 1958 L. R. PRlTlKlN SANDING DEVICE Filed Aug. 20, 1956 v INVENTOR. [ou/.s E FEIT/K1N United States Patent O SANDING DEVICE Louis R. Pritikin, West Los Angeles, Calif.

Application August 20, 1956, Serial No. 604,893

. 4 Claims. (Cl. 51-187) This invention relates to a sanding block of the type used for sanding callouses and the like on -the surface of the skin, although it may be used for other purposes.

A general object of this invention is the provision of a sanding block holding several pieces of sandpaper so that when one piece is worn out it can easily be torn from the block exposing a fresh piece in position for use.

Another object is to provide a sanding block of extremely simple and inexpensive construction, which may embody simply a pair of complementary sections providing pairs of jaws at the respective ends of the device, for clamping the ends of sandpaper strips.

A further object is to provide such a sanding block wherein the ends of the sandpaper strips will be drawn into the block as the sections of the block are brought to- -30 gether, thereby tensioning the sandpaper in the working area thereof.

Yet another object of this invention is fthe provision of an arrangement for supporting the sandpaper in a manner to provide a cushioning action in the sanding operation.

More specifically, the invention contemplates .a sanding block embodying a recessed member having projecting curved ends around which the end portions of the sandpaper strips are drawn into a recess defined between said curved ends. A cap member, complementary to the first member, engages said ends and clamps them in the recess. In one form of the invention, .a bolt extends through the cap member and threads into the recessed member. As the bolt is tightened the center portion of the recessed member is drawn toward the cap member, v

and at the same time tension is applied between the ends of the recessed member, whereby the latter is bowed upwardly, forcing its ends -outwardly and allowing the cap memberto drop further into the depression. 'The rough surface of the sandpaper strip grips the ends of the cap, causing ends of the strips to be drawn further into the depression, with the result that tension -is developed in the strips. The upward arching of the bottom of the recessed member provides an air cushion for the usable central portion of the sandpaper.

Other objects and advantages will becomeapparent as the ensuing specification is read with reference to the appended drawing in which:

Fig. 1 is a side view of a sanding block with sandpaper in place ready for use;

Fig. 2 is an exploded side view showing the sanding block disassembled;

Fig. 3 is a top view showing a piece of sandpaper being torn from the block;

Fig. 4 is a sectional side view showing a modification of the sanding block.

The sanding block is comprised generally of a recessed lower member 10, and a complementary upper member (cap) 11. Member 10 normally has a flat bottom face 12 and a recess 13 in its upper side, while the lower surface 14 of member 11 is complementary to depression 13 and has sharpened ends 15. A bolt 17 projects through an aperture in the center of member 11 .and threads into member 10. Member 10 has relatively thick end sections joined by a relatively thin medial web of su'icient flexibility so that .it can be bowed from its unstressed condition shown in Fig. 2, with its normally flat bottom face 12, to its arched condition shown in Fig. 1, with a concave bottom face indicated at 12. The end sections. are inclined upwardly to provide arms for pressure-loading coaction with the end portions of sandpaper strips 18.

Sandpaper strips 18 are easily attached to the block by laying several strips along the flat face 12 with the member 11, but the sandpaper tips hold the ends 15 and 16 apar-t forcing surface 12 to bow upwardly and thereby moving the ends 16 outwardly. The outward movement of ends 16 allows member 11 to slip further into space 19, and the rough surface of the sandpaper engaging member 11 causes it to be gripped and drawn further into depression 13 with the members 10 and 11 thus placing a great deal of tension upon the strips of sandpaper. across `the bowed surface 12' which provides cushioning for the usable area of the sandpaper.

When a strip of sandpaper becomes worn and useless, a sharp object such as a fingernail le or pair of scissors may be inserted between the used strip and the adjacent I strip and used to tear the taut strip in two. Each piece Z2 of the used strip may then be neatly torn from the block by pulling it against sharpened edge 1S.

A modification of the invention (Fig. 4) contemplates a U-shaped lower member 10 with a pair of outwardly' v curved arms 23 and -normally having a flat bottom. Sandpaper strips are wrapped about the bottom of member 10 with their tips extending over the ends of arms I 23. A cap member 11', complementary to the depression in the lower member 10', is forced into the depression.

As it is inserted, the ends 24 of the upper member must force arrns23 apart and therefore bow the bottom upwardly providing an air cushion for the sandpaper. As f ends 24 force arms 23 apart, they place downward fri c' tional pull on the sandpaper tips and the coarse surface facing ends 24 prevents slippage, whereby these tips will be drawn into the depression along with cap member 11' resulting with tension being placed on sandpaper 18.

Sides of cap member 10 are provided with elongated depressions 25 t-o receive the finger tips and facilitate grasping of the cap member.

The sandpaper strips 18 are sterilized, as by treatment with ultra-violet rays, prior to packaging thereof.

The arms at the ends of the lower member are generally of crescent shape, as shown, defining inner faces which are concave and which, at the tips of -the arms, are slightly convergent upwardly so as to overhang the depression, thus providing for locking the ends of the cap member into the depression, with the interposed tips of the sandpaper strips likewise locked to the sanding block. In this connection it may be noted that the invention contemplates a hard material (e. g. unplasticized synthetic resin thermoplastic material such as methyl-methacrylate) capable of developing fairly high spring loading between the arms of the lower member as to spread apart by the interposed cap member and strip tips. This spring loading, causes the arms to securely grip the strip tips against the.

Patented Jan. 7, 1958.

This tension causes the sandpaper to be taut I ends Yof the cap member so that they cannot possibly becomeeloosened: Thus the -operative' midportions ofthe sandpaper strip are etectivelystretched between the ends ofthe lower member,.under a. tension such as. to provide. a-cushioningjaction"wherev these stretchedmidi-porti'ons of the strips areslightly spaced from .the bottom off'the lower member'due to the arching of the bottom web thereof under said tension. The cap memberhas rounded'.` end'. faces adapted toA establish secure frictional engagement withthe sandcoatings of said. strip"tipsone of said. end? faces being adapted to pivotally fulcrum within the .con-

cave end face of one arm and the other being adapted to.exert a camming action against the tipl of. the. other arm when subjected to pressureforcing: the capl .member into said'depression, whereby to spread .the .arms and ,per-

mit the cap member to enter'said depression through said restricted pass, said'rounded ends of. the capvmemb'er becoming ,locked between said concave inner facesto securely mount the sandpaperstrips upon said lower,mem.

ber.

I claim:

l. In a miniature sanding block for holding aplurality of sandpaper strips for cosmetic use: a lower member: which in longitudinal section is of shallow U-form, said, lower member including a medially disposed bottom web. and a pair of arms projecting .upwardly from the respective. ends thereof and dening with said web, an elongated depression, said web being exibleandsaidendxsections being. relatively inflexible whereby said bottom member.y may bebowed in responsetospreading end pressure: applied `.tot.said..arrns; a cap havingrespective .ends adapted:- to.be related to. the facesof said .armswithinfsaid recess to,pr.ovide.pairsV of jaws. at the respective. ends of .the block, between which the-.ends of the sandpaper strips maybeclamped; .and means for applyingbetween said lower memberand cap, forces drawing said capi into. said depression, causing the ends of said capto exert a spreadV ing, action through the interposed ends of thev sandpaper strips againstsaid armsLandto therebyA placethesand-J paper stripsnmder tension-and tocause '.said lowenmem-V ber to bow' toward said capso as to provide. afcushioning space. between the stretched. sandpaper strips.` and I the bottom ..face of said. lower member.

2,L In aminature sandingfblock for holdinga plurality: offsandpaper. strips for cosmetic use: aalower. member. which .in longitudinal .section vis of shallow. U.-,form, said; lower member includinga mediallygdisposedf:bottom web. anda-pairof arms projectingupwardly fromltherrespectivev endsfthereofand defining, with .said.web, van` elongated de.: pression, said web being liexible'and. said. end sections beingrelativelyinexible.whereby-said bottom member may bebowed .in .response to spreading. encl'v pressurel applied:` ltosaidarms; `a .cap havingrespective ends .adaptedztobe related .to the faces of saidv arms;` within lsaidirecesswtoV provide. pairs .of jaws. at theerespective ends I.of :the block, between. .which the rends of, the sandpaper vstrips may be clamped; anda connector;engaged-'between saidtcapnand:4 bottom member and operable-y to.v simultaneously draw saidweb toward saidcap while:applyingtpressureafrom the endsV ofsaid -cap .through the; interposedends of the sandpapcr'stripsto said arms', wherebyito place the sandpaper strips under tension'andto cause vsaid lower member to bow toward sairlxeapso'` as to'provide a cushioning space elongated depression, said web being exible and said end sections being relativelyinflexible whereby said bottom member may be bowed upwardly in response to spreading end pressure appliedvto saidf'arms;` a substantially rigid integralv caphaving respective ends inopposed relation to the faces of'saidarms within said'recess to provide pairs of jaws at the'respective'endsroflthe-block; a plurality of sand paper strips having ends clamped between said jaws and spacing the cap and lower member apart and having intermediate portions in opposed relation t0 said web; and. a. connectorY engaged betweensaid .cap and. gbottom'member and. operable to,simultaneous1y draw.' said, web toward. said cap while. applying .pressure zfrom thea ends', oflsaidcapto the. interposed endsYof said. sandpaper strips to. said armspwhereby tta-.placel saidsand. paperstrips under -tensionand .to .causersaid lower memberl to bow toward saidfcap so asto cause saidbottom :face to become concave, ...thereby providing. a.: cushioning; -space betweensaid intermediate4 portions of.the.-sandpaperfstrips and-Qy said Vbottom facey 4-.-. Inqaminiature:sandingblack. for cosmetic use: ai lower member which inlongitudinalsectionis of shallowf Ufform, .said lower .member having a normally/.,-tat lower face and includinga medially disposedzbottom web =andapair.. of- "arms .projecting upwardly from the respective .endsthereoffand 'dening. with said` web an elongated. depres sion, said web being flexible and said end sectionsbeingA relatively. iniexible whereby said bottom' member may,y be bowedr upwardly in response tov spreading end` pressuref applied to.. said i arms; a .substantially rigid integral .-cap..l having respective ends in opposed relation to the faces .of-.

saidarms within. said recess to provide pairs yof jaws at 4the respective ends ofthe block; a pluralityyofl sandpaper;- strips having .ends clamped betweensaid. jaws and spacing; i the .,cap. andlower member apart and :having intermediatey portions inopposed .relation to..fsaidweb; and a connector.l

engaged between said capp andbottom member. and fopen abletosimultaneously .drawsaid web toward saidrap..

whi1e.applying pressurefrom theiendsaof said cap tothe. interposed.ends..of said-sandpaper. stripstosaid arms, whereby to place .saidtsandpaper strips under tensionand to .cause ...said i lower 'member to bow toward said so. t as tol causeisaidbottomrface to become :conca-vee.thereby;y providing acushiom'ng spacebetween .said-intermediate.-

portions ofthe sandpaper strips andisaidlbt'rttom` face.

References Citedjinthe le of this patent UNITED. STATES; PATENTS 736289 Murray Aug, 11g1'9o3' 809,615"V Hopkinsv Ian. 9; 1906 1,737,135 Windfeldt Nov. .26., 1929 2,457,076 Williams et al Dec; 21, 1948 23357308' Schubert Nov.y 3;,'19'531' FOREIGN PATENTS 403,801 Italy May 8,{19431 

